Developing Film with Coffee
I love coffee. I do. It’s a staple of my diet, and my love for the beverage is one of the reasons why I founded Skeleton Brew Coffee. It is something near and dear to my heart and stomach. I enjoy hot coffee, (some) flavoured coffee, iced coffee, coffee slushes, and the list goes on. I have even enjoyed a good decaf, as sacrilegious as that might seem.
Of all the types of coffee I enjoy, one that very rarely makes the list is instant coffee. I’ve drank it before. If I am ever in a very tight pinch and in a rough way I might drink it again. Given the choice, however, I have found I don’t have much need for it.
Imagine my surprise, then, when I finally did discover a reason for purchasing instant coffee: to develop film.
Film photography is another love of mine. I find it far more satisfying than digital photography. What I do not like about film photography, however, is the cost of getting the film developed. That is one of (though not the only) reason that I usually photograph with black and white film; it’s easier to develop at home. And with instant coffee, developing film becomes chemical free!
“Caffenol” is a simple film developer made from household ingredients including instant coffee, vitamin C (ascorbic acid), and washing soda (sodium carbonate). The process works because instant coffee contains caffeic acid, a natural reducing agent, which, in combination with vitamin C, reacts with the silver halide crystals in the film’s emulsion. This reaction reduces the exposed crystals to metallic silver, forming the image. Washing soda adjusts the solution’s pH, enhancing the development process.
It’s worthy to note that while the developing solution itself is chemical free, the final solution after developing the film will have silver halide in it, so should be disposed of properly.
Developing film in this manner is very much trial and error; different films require modifications to the recipe, and there are many recipes available on the internet; some people have even used red wine, which is an idea I would also like to try!
This is the recipe and the film with which I have had the most success:
- Film type: Ilford Delta 100
- Instant coffee: 54 grams (2 tablespoons)
- Washing soda (sodium carbonate): 16 grams (4 teaspoons)
- Vitamin C (ascorbic acid): 16 grams (4 teaspoons)
- Water: 1 liter (about 34 ounces), lukewarm.
Directions
Mix the instant coffee with the lukewarm water and stir until completely dissolved. Take your time. Any remaining coffee granules run the risk of scratching the film.
Add the washing soda. Again, stir until completely dissolved. You don’t need to be in a hurry. In fact, while you’re waiting for it to be dissolved, make your own coffee!
Add the Vitamin C. Follow similar steps. Be patient. Take your time. Dissolve it all.
Finally, develop the film as per normal. I am going to assume that you already have a developing cannister and such; if this is your first time developing film, I highly suggest you use a proper chemical developer to get your routine down.
I like to develop the film for 10 minutes. I’ve built a contraption which gently agitates the developing cannister automatically so I can enjoy my own coffee at the same time; I’ll have another post on that at some point.
Ultimately, rinse off the film, squeegie it dry, and do whatever it is you enjoy doing with your film. Here are some of my results using a Minolta X-370.
